Mg-doped TiO2 boosts the efficiency of planar perovskite solar cells to exceed 19%

Abstract

Mg as an effective ion dopant has been introduced into compact TiO₂ ETL for planar perovskite solar cells. It is found that Mg doping can shift the Fermi energy level of the ETL upward and decrease the resistivity of the TiO₂ film. Carrier transport velocity is thus enhanced and high charge collection efficiency has been achieved at high bias voltages, leading to a higher fill factor (FF) and better cell efficiency. More than 19% power conversion efficiency has been obtained.